No spark - 1982 GS1100GK - faulty igniter?

[Guest]

After experiencing intermittent rough running/poor accelaration, seemingly randomly with cold or hot engine I cleaned the few electrical contacts I hadn't cleaned before on my 1982 GS1100GK.

I want to emphasize that the engine was capable of running smoothly and strong between the episodes of poor acceleration.

Before the final cleaning the sparks were weak. Now I don't have any spark anymore and I tested the ignition following the instructions of this link: http://members.dslextreme.com/users/storagecliff/images/electrical_odd-n-ends.html#A17 (Testing the ignition system by Mr. Matchless).

My bike seems to have OEM coils and ignition system.

Resistance of the secondary coils is ~12.5 k Ohms (with plug connectors disconnected).

With the plug connectors resistance is ~22 k Ohms for both coils (Suzuki manual says it should be ~30-40 K Ohms).

Battery, plug connectors and plugs are new.

Primary winding for both coils: 4.3 Ohms.

Resistance of signal generator pickup coils: 164 Ohm (same for both; OK according to Suzuki shop manual).

Between the orange/white and the black/white wire going to the igniter there is only 11.2 V. Battery voltage is 12.7 V. Could the low voltage to the igniter be the issue?

I also simulated the voltage coming from the pickup coils by using a 1.5 V battery following the procedure of the Suzuki shop manual. No spark.

If the relatively low voltage that goes to the igniter is not the issue things point to the igniter being faulty.

What do you recommend to fix this?

Find/eliminate the cause for the relatively low voltage going to the igniter?

Replace the igniter with a used one? It looks like OEM igniters are no longer available.

Get an aftermarket ignition system?

Thank you in advance for your help. Riding the bike is pure pleasure when it runs well and I am eager to get to the bottom of this!

 

[Redman]

Seems like you are doing a good job of checking things.

I cant say about the low ohms of coils, nor can I say about the low voltage at ignitor.

But what would also be good to know is the voltage at the coils. The voltage at org/wt wire to ground.
I suspect it will be lower than at ignitor, and that will be a likely suspect.
Also check and see how low it goes when cranking starter, and how low battery goes.

If that is real low, THen we can talk about trying to trace where are loosing the voltage .... .. and / or talk about the coil relay mod.

 

[Guest]

Thank you, Redman.

Voltage at the coils: 10.8, goes down to 9.7 when cranking.

Battery voltage: 12.7 V, goes down to 11.9 when cranking

 

[Redman]

Great that you can do that testing. Loosing over 2 volts from battery voltage to where gets to the coils. Maybe loosing some at fuse block, some at ignition swtich, same at connection in wiring harness, ...... or some at each that all add up (as was in my case a few years ago).

9.7 is fairly low voltage at the coils, I dont really know at what low voltage the coils dont produce a spark to jump the gap, but is is somewhere around there.

As a temporary test, you could run a wire from battery+ or maybe the aux terminal on fuse block to the coils somehow. Either crimp on connectors, or maybe sneek the wire into the existing connector at one of the coils. THis will be like "hot wiring" it to bypass a lot of connectors and the igntion switch to get closer to full battery voltage to the coils. Turn on key, and give it a try.
If that produces much better results, you could then try to find where are loosing the voltage and fix it.
Or we can talk about finding you instructions for the Coil Relay Mod, which is essentaill a coil to connect a jumper wire to hot wire power to the coils. And the coil to operate based on a circuit that swtiches on with the ignition switch.

 

[Guest]

Thank you, I will do the temporary test first. When I run a wire from the positive battery terminal to the coils, do I leave the existing orange/white cables connected to the coils?

I found instructions for the coil relay method: http://gsarchive.bwringer.com/bikecliff/images/coil_relay_mod.html Are these (or the links in it) the best instructions?

 

[Rijko]

Thank you, I will do the temporary test first. When I run a wire from the positive battery terminal to the coils, do I leave the existing orange/white cables connected to the coils?

You could, but is not necessary.
Just don't leave the permanent voltage on the coils too long as you may blow up the coils that way.

I found instructions for the coil relay method: http://gsarchive.bwringer.com/bikecliff/images/coil_relay_mod.html Are these (or the links in it) the best instructions?

If i find a coil relay mod on a bike, that sounds alarm bells.
To me that's an unsolved issue on the bike, bypassed by this mod, which could still cause issues.
My advice : find the issue and solve it.
Clean connectors and handlebar switches and you should have proper voltage on your coils and igniter.
And who knows : cleaning connectors, handlebar switches and contact may solve other issues or prevent them.

 

[Guest]

Thank you, Rijko. I cleaned all connectors I saw and also the ignition switch, the kill switch and the fuse block.

In general, the bike is in good condition and clean and I have seen no corrosion on the connectors; I cleaned them anyway with Deoxit spray.

I am eager to find the source of the voltage drop.

 

[Rijko]

no corroded connectors ? You are a lucky guy, most are very corroded.

I am looking at the '82 GS1100G wiring diagram here : http://gsarchive.bwringer.com/bikecliff/images/GS1100G_1982_wiring.jpg
For some reason the GS1100GK one gives me issues but it should be very similar.

Since you also have low voltage at the ignitor, the issue must be further up.
You can trace the orange wire on the picture from coils to ignitor, to the kill switch.
That's where i would see if you have proper voltage and work further through 2 connectors towards the fuse box.

 

[Guest]

Thank you. I connected the coils directly to the + aux terminal of the fuse block. Still no spark.

I also cleaned the starter button by spraying Deoxit in all accessible openings - after getting access to the inner parts by unscrewing the two halves attached to the handlebar- and actuating the button multiple times.
I did not disassemble the switch completely, was worried that I wouldn't be able to reassemble it correctly. Is full disassembly required for proper cleaning?

Should I also "hotwire" the igniter to ensure full voltage to test it or would 11.2 V to the igniter suffice to test it? Trying to figure out if I have to replace it.

I am in the process of finding/double-checking any remaining connections of the ignition system I may not have cleaned yet.

 

[Rijko]

To rule out the coils there is a quick and dirty way.
You've got good 12 volt on the coil now, so rubbing the signal
wire to ground should produce a spark.

There is a way to test the igniter but i am in a hurry now,
hope someone else can post it.
Giving the igniter good 12V is surely worth a try.

 

[Guest]

Thank you, I tested the coils according to the coil test Youtube video from your post.

There was a weak spark from only one spark plug, no sparks from the other three plugs. There were strong sparks though between the negative wires when I removed the wires from each other. Why wouldn't I see the sparks from the (new) plugs? Wrong spark plug connectors?

The bike started well and ran very well a few weeks ago - interrupted by occasional rough running - with the same coils, spark plug connectors and spark plugs. It got worse over time after I double-checked all connections and tried to find the cause for rough running. I double-checked that everything was properly connected/reconnected.

I am wondering if I may have damaged the igniter when I checked for sparks and perhaps may not have grounded the plugs properly to the engine block.

Is my assumption correct that only one of the plugs has to be grounded to avoid damage to the igniter or do all four plugs need to be grounded at the same time?

I am trying to locate where the voltage drop occurs. Should I measure voltage between the two Orange/White cables just downstream of the kill switch and starter button?



Which other spots should I check besides the ones I already checked (see posts above)?

Thanks again!

 

[Rijko]

You've got it.

You can measure how many volts are going into the handlebar switch, the left wire you're pointing at.

The other one shows how many volt are exiting the handlebar switch towards coils and igniter.

Another point to check is the green/yellow wire, which sends 12V to the starter relay when the button is pressed.
Measure voltage at the connector, also be good to unplug the yellow/green wire at the starter relay and see how many volts arrive there.

The spark plug caps should screw into "fresh" meat, did you check for corrosion in the spark plug wire when you mounted the new caps ?
Usually it takes clipping half an inch off the wires to get at the clean wires.

I usually ground 1 spark plug well, using a wire like in the video and switch that one with the coils i am testing.

I just helped a friend with a GS1000 with his electronics, he became very frustrated when he saw me pointing out almost every single connection in the ignition circuit being corroded, losing voltage, etc. Just hang in there, solve 1 issue at a time and you will get there :encouragement:

 

[Guest]

Bedankt! I will conduct these voltage drop measurements.

I cut off ~15 mm of the spark plug wires to make sure the connectors connect to unoxidized metal.

What do you think about the coils based on the results of the coil test?

 

[Rijko]

Bedankt!

you noticed i'm Dutch, hahaha must be my language that gave it away, not my native tongue ...

What do you think about the coils based on the results of the coil test?

i measured that low before, and the coils worked fine.
Not saying they're good, just that they are very rugged and usually work until you get no reading at all.

 

[Guest]

you noticed i'm Dutch, hahaha must be my language that gave it away, not my native tongue ...

Well, "Rijko" sounds Dutch to my German ears and ultimately your location confirmed it

i measured that low before, and the coils worked fine.
Not saying they're good, just that they are very rugged and usually work until you get no reading at all.

I meant the spark test. Could the coils be good even though I did not see a spark on 3 of the 4 plugs, just on the wires?

 

[Rijko]

Could be. Maybe the plug was not grounded well during the test.
No harm in trying them anyway.

 

[Gorminrider]

I wouldn't worry too much about "voltage drops" when your ignitor tests bad.

You'll always have voltage drops with coils and lights loading a tiny battery but sure checking connections is always a good thing. Pull the headlight fuse. That should help improve the Voltage of the remaining circuits throughout.

Is my assumption correct that only one of the plugs has to be grounded to avoid damage to the igniter or do all four plugs need to be grounded at the same time?

all plugs should be grounded. The plugs fire in pairs.

 

[Rijko]

all plugs should be grounded

yeah .. i did not pick up on that.
If you ever want to see a spark from any spark plug, it should be grounded.

I usually ground 1 spark plug well, using a wire like in the video and switch that one with the coils i am testing.

 

[Gorminrider]

yes, good idea=One at a time using the same "known good" plug. I actually made myself a special test plug with a grounding clamp ....leaving the others in place

 

[Guest]

You can measure how many volts are going into the handlebar switch, the left wire you're pointing at.

The other one shows how many volt are exiting the handlebar switch towards coils and igniter. I checked the voltage difference between the two Orange/White wires, it is 0.17 V. Is this in the range that one would expect?


Another point to check is the green/yellow wire, which sends 12V to the starter relay when the button is pressed.
Measure voltage at the connector Only 10 V at the connector. Should I completely disassemble the starter button for a thorough cleaning? I connected the positive cable of the multimeter to the connector and the negative cable to the negative battery terminal. , also be good to unplug the yellow/green wire at the starter relay and see how many volts arrive there. 11.1 V arrive there.
...

Thank you Rijko and Gorminrider for your input.

Please let me know what you think about these measurements.

I am wondering what my next steps should be. Retest the igniter with pulled headlight fuse?